High temperature catalytic metal field effect transistors for industrial applications

Field effect chemical sensors, utilising silicon carbide as semiconductor, can be operated at high temperature and in rough environments. Gas sensitiv e field effect transistors, MISiCFET, are now developed (ACREO, Kista in Sw eden). This will increase the number of possible applications for field eff ect gas sensors. The first batch of MISiCFET devices is possible to operate in intermittent pulses of hydrogen/oxygen up to 775 degreesC. At temperatu res above 600 degreesC, the gas response of the MISiC devices has very shor t time constants for a change between oxidising and reducing atmosphere and cylinder specific monitoring of a combustion engine has been demonstrated. Other industrial applications, like exhaust diagnosis and flue gas monitor ing, have been demonstrated by the use of MISiC Schottky diodes at lower te mperatures, 200 degreesC-500 degreesC. (C) 2000 Elsevier Science B.V. All r ights reserved.